Holding device



4 H I IM 2 5 ll w w T U 4 n a 4 w 8 QR. 8 m M 2 w m I W 9 B 2 2 O 4 z a F 82 $43 INVENTOR Joseph W. Sreiner WITNESSES VZILM; X M 34 ATTORNEY United States Patent 0,

2,989,721 HOLDING DEVICE Joseph W. Steiner, North Olmsted, Ohio, assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed Oct. 21, 1957, Ser. No. 691,307 4Claims. (Cl.339-108) The present invention relates to a holding device and more particularly to a film cutout holder for use in series lighting circuits.

In series lighting circuits, it has been common practice to use lampholders incorporating a film cutout holding device combined with mating contacts for engagement with contacts in a receptacle. Such components have been standardized and accepted by the industry. In these devices a standard disc-shaped film cutout is held between two resilient socket prongs. Generally, removal and insertion of the film cutouts is difiicult and inconvenient in view of the fact that the prongs are urged into engagement with each other and are fairly stiff. In replacing or inserting a film cutout, it is necessary to first separate the prongs. However, due to the resiliency of the prongs, this is diflicult to accomplish particularly in view of the elevated heights at which a Serviceman normally works in street lighting work, and it usually requires the use of a tool of some sort.

Accordingly, one object of the invention is to provide a new and improved film cutout holder of a construction to permit ready separation of the prongs by hand. A more specific object of the invention is to provide a new and improved film cutout holder having prong tips of a non-symmetrical shape so as to provide convenient finger grip areas at one side of each of the prongs.

These and other objects of the invention will become more apparent upon consideration of the following detailed description of a holding device constructed in accordance with the principles of my invention, when taken in conjunction with the attached drawings, in which:

FIGURE 1 is an exploded perspective view of the outer ends of the prongs of a film holder constructed in accordance with the principles of my invention, and showing a film cutout located between the ends thereof;

\FIG. 2 is a cross-sectional view of a socket for a lamp which has a pair of prongs constructed in accordance with the principles of my invention extending outwardly from one end thereof; 7

FIG. 3 is a side elevational view of the assembly shown in FIG. 1 in the normal closed position; and

FIG. 4 is a longitudinal cross-sectional view of the assembly shown in FIG. 1 in the operative position.

In FIG. 2 there is illustrated one type of standard lampholder for the purpose of supporting a lamp in a series circuit. As shown, the lampholder 2 comprises a socket body 4 having a central recess 6 in one end. A screw shell 8 is located within the recess 6. The body 2 may be formed of any suitable insulating material and is commonly formed from porcelain. The shell 8 is formed with standard screw threads to threadedly engage the threaded base of a standard lamp, not shown, for the purpose of electrically energizing such a lamp, and is formed from any suitable electrical conductive material, such as an alloy of copper. As shown, the lower edge of shell 8 is provided with an integral extension and an angularly inwardly extending ear 10 located in a recess formed in the. base of the body 4. The inwardly extending car 10, forms one terminal for-the film cutout holding prong 29. Located on top of the ear 10, is a yoke 11 which extends along a portion of the inner periphery of the central recess 6. The shell 8 is rigidly secured and electrically connected to prong 29 by a screw 2,989,721 Patented June 20,1 961 12 extending through the yoke 11 and the ear 10 of the shell 8 and through a clearance opening 14 in the lower end of the body 4 so as to threadedly engage a nut 15 at its outer end. The yoke 11 may be further secured to the body 4, by other screws, not shown, to firmly seat the yoke in the recess 6.

In order to electrically energize the center contact, not shown, of a standard lamp base, a centrally located contact assembly 16 is resiliently supported centrally in the recess 6 of the body 4. The construction of the contact assembly 16 may be of any known type. As shown, the contact assembly 16 may include a resilient radially outwardly extending connector 18 which is reversely bent at its outer end to provide an ear 20 in engagement with the bottom of a recess formed at the inner end of the recess 6 of body 4. The ear 20 is secured to the body 4 by means of a screw 22 extending through a clearance opening 17 in the body 4 and is threadedly secured at its outer end by means of a nut 24.

The heads of the screws 12 and 22, are recessed within the body 4 so that no electrical circuit will be made between the base of a standard lamp, not shown, and

the screws 12 and 22. Recesses 44 are made in the lower portion of the body 4 to receive the ends of screws 12 and 22 and the nuts 15 and 24. The screws 12 and 22 should not extend beyond the lowermost portion of body 4 to conform to industry standards. Screws 12 and 22 and nuts 15 and 24 also secure the prongs 28 and 29 to the closed end of body 4 by the flanges 31 and 33 on the prongs. A bumper pad 30, made of a heat resistant, electrical insulating material is placed on the lowermost portion of the body 4. The bumper pad 30 is provided with a flat ring shape to abut the screws 12 and 22 and the. body 4. The outside diameter of the bumper pad 30 is slightly less than the outside diameter of the body 4 immediately adjacent to the bumper pad 30. The inside diameter of bumper pad 30 is large enough to allow the prongs 28 and 29 to extend outwardly therethrough away from the body 4.

The prongs 28 and 29 are made of flat, substantially rectangular strips of a resilient conductive material, such as a copper alloy. Prongs 28 and 29 have flange portions 31 and 33 which fit tinto the recesses 44, respectively. The flange portions 31 and 33 have openings and are secured in the outer recessed portions 44 of body 4 by the nuts 15 and 24 on the screws 12 and 22. By connecting the flange portions 31 and 33 to the screws 12 and 22, the prongs 28 and 29 are shunt connected across the lamp circuit. An insulating film cutout 32 normally prevents current flow between the prongs and thus normally permits the lamp to be energized. The prongs 28 and 29 extend outwardly away from the body 4 through thecenter opening of bumper pad ring 30, convergently, to. face each other at their outer ends.

As shown in FIG. 4, the prongs are arcuately bent out wardly from each other adjacent their outer ends at 35. and 37, and then reversely bent as indicated by the reference characters 39 and 41. Also the prongs are arcuately bent as indicated by the reference characters 43 and 45 to form fiat tips 34 and 36, outwardly extending from the body 4. The angle at which the tips 34 and 36 must be bent is such that when the film cutout 32 is removed, the tips 34 and 36 will be substantially parallel to each other so that their inner contact surfaces will be in flush engagement. The prongs 28 and 29 are biased towards each other to engage under relatively high contacting pressure when the cutout 32 is removed.

The construction'so'far described is that of a standard series street lighting lamp socket with a film cutout, and is the construction with which the invention can particularly be used, although the invention is not limited to this use.

In operation, the resilient prongs 28 and 29, which are of identical shape, hold the film cutout 32 between the flat ends 34 and 36. The film cutout 32 is of a normally insulating character capable of conducting current under certain abnormal conditions. In normal operation, voltage is supplied across the prongs 28 and 29 to electrically energize the lamp socket. Upon lamp failure, the cutout 32 is ruptured or converted to an electrical conductor due to the increased voltage applied across the prongs 28 and 29. When the lamp is replaced, it is necessary to also replace the film cutout 32.

It is often the case that when the film cutout 32 is to be replaced, it is diflicult to separate the prongs 28 and 29 at the tips 34 and 36, because the prongs are resiliently biased towards each other under relatively high pressure. To insert a tool as a fulcrum between the prongs 28 and 29 is not too desirable because the prongs may be permanently displaced relative to each other as by being stressed beyond their elastic limit, and therefore no longer capable of engaging each other.

It will subsequently become apparent that I have provided a novel form of contact prong providing finger grip portions within the normal confines of standard type prongs for easily separating the prongs by hand without the use of tools.

Referring particularly to FIGS. 1 and 3, the illustrative embodiment of the invention has the prong tips 34 and 36 shown as each comprising a substantially fiat area located outwardly of the outermost bent portions 43 and 45. The tips 34 and 36 have at their outer ends at one side a curved edge portion 46 which joins that side edge to the straight outer end edge 50. The curved portion 46 defines a circular are having a radius of a length preferably equal to one half the width of a prong 28 or 29. Since the width of the prongs 28 and 29 is about the same as the diameter of the cutout 32,'the radius of curved portion 46 is thus about the same as the radius of the cutout 32. The opposite sides of the prong tips 34 and 36 have a substantially rectangular corner 38, which is formed by the intersection of the straight side edge 48 and the straight outer end edge 50. It will be noted that the straight outer end edge 50 is tangential to the curved edge portion 46 and at a right angle to the straight side edge 48. Similarly, the curved edge portion 46 is tangential to the side edge opposite that side edge 48 located on prongs 28 and 29.

Inasmuch as the prongs 28 and 29 are mounted so that the corners 38 of the prongs are at opposite sides of the assembled prongs, there are substantial areas at the corners 38 of each prong at the inner sides thereof which are exposed by the oppositely located curved edge portion 46 of the other prong. These exposed areas can be easily engaged, for example by the thumb or forefinger of a repairman, to exert force on the prongs in opposite directions to separate them. A film cutout 32, can thereby be easily removed when lamp service is desired, and it will not necessitate the serviceman prying the prongs 28 and 29 apart with a tool and possibly damaging the unit by bending the prongs out of substantially parallel alignment.

It will be apparent that this invention provides for a quick, convenient means for inspecting or replacing film cutouts used in lighting apparatus, to eliminate lost time and give maximum efficiency. Accordingly, while the present preferred form has been specifically illustrated and described in accordance with the patent statutes, the invention is not limited to this particular form and design, as it will be apparent to persons skilled in the art that the invention may take other specific forms and may be employed for other applications wherein one or more of the features thereof may be employed with particular advantage.

What is claimed is:

1. In a lamp holding assembly, a holder for a film cutout, said holder comprising a support, a pair of opposed, elongated and generally rectangularly shaped contact arms resiliently mounted at one end thereof on said sup port to extend outwardly from said support, said contact arms being normally biased toward each other into generally opposing relation so as to hold said cutout be- I tween their outer end portions, a segment of the outer end portion of each of said contact arms being removed within the generally rectangular contour of said contact arms, the end portion of each of said contact arms extending over the removed segment of the opposing contact arm to provide finger grip means for separating said contact arms and removing said cutout.

2. In a lamp holding assembly, a holder for a film cutout, said holder comprising a support, a pair of opposedelongated generally rectangularly shaped contact arms resiliently mounted at one end thereof on said support to extend outwardly from said support, said contact arms being normally biased toward each other into generally opposing relation so as to hold said cutout between respective outer end portions of said contact arms, said end portions of said contact arms being generally planar and being generally parallel to each other, and each of said ar-m end portions including a finger grip section and a removed section, the finger grip section of each of said arm end portions extending over the removed section of the other of said arm end portions and being located within the general rectangular contour of its contact arm so as to enable said contact arms to be separated and so as to enable said cutout to be removed.

3. In a lamp holding assembly, a holder for a film cutout, said holder comprising a support, a pair of opposed elongated contact arms resiliently mounted at one end thereof on said support to extend outwardly from said support, each of said contact arms being of generally rectangular contour, said contact arms being normally biased toward each other into generally opposing relation so as to hold said cutout between respective outer end portions of said contact arms, said outer end, por tions of each of said contact arms having one edge ex tending from a point on an outer lateral arm edge inwardly of said outer lateral arm edge to a point where it intercepts an adjacent longitudinal arm edge, a finger grip section of said end portion of each of said contact arms extending beyond said one edge of the opposing contact arm so as to enable said contact arms to be, separated and so as to enable said cutout to be removed.

4. A holder for a film cutout, said holder comprising a pair of elongated contact arms, means for supporting one end of each of said contact arms so as to enable respective free end portions of said contact arms to be biased toward each other into generally opopsing rela tion and thereby to hold said cutout therebetween, said free end portions being generally rectangular and being substantially parallel to each other, and means for enabling said free end portions of said contact arms to be separated manually for removal of said cutout, said enabling means including a finger grip section of each of said free end portions extending over a removed section of the other of said free end portions within the generally rectangular contour of said free end portions.

References Cited in the file of thispatent UNITED STATES PATENTS Re. 14,341 Jones Aug. 7, 1917 1,548,656 Butler Aug. 4, 1925 1,908,568 Steinmayer May 9, 1933 2,050,364 Morton Aug. 11, 1936 2,243,741 Rowe May 27, 1941 

